Reduction-gearing



F. HODGKINSON.

REDUCTION GEARING.

APPLICATION FILED FEB. 4. 1919.

Patented Nov. 2, 1920.

INVENTOR.

By %;a ATTORNEYMi.

' Original application filed June 16, 1916,

UNITED STATES rarlaiar oi-"Fica;

FRANCIS HODGKINSON, OF EDGEWOOD, PENNSYLVANIA, ASSIGN HOUSE GEAR &DYNAMOMETEB COMPANY, A CORPORATION OF PENNSYLVANIA.

T 0 all whom it may concern:

Beit known that I, FRANCIS HonemNsolv, acitizen of the United States,and a resident of Edgewood, in the county of Allegheny and State ofPennsylvania, have made a new and useful Invention in Reduction-Gearing,which is a division of application, Serial 0. 103,993, filed June 16,

1916,) of which the following is a specimation. A further object is toproduce a multiple .reduction gearing capable of transmltting largepowers in which .the separate gears are so combined and arranged as toobtain a more uniform distribution of stressesand strains than hasheretofore been obtained in gears of the same speed ratio and power, andin which means are employed for compensating for deflection ordistortion of the gears or gear carryingmembers forming a part of thegearing.

The gears of a power transmission gearing are liable to and do distort.tortion may be either torsional or a transverse deflection and is moremarked in relatively long gears and gear carrying'members.

A further object of the invention is there fore to produce a reductiongearing capa-.

ble of transmitting large powers and of accomplishing relatively greatspeed transformations in which means are employed for minimizing thecross bending or transverse deflection of the relatively long gears .orgear carrying members.

In reduction gearing designed to trans' mit large powers it isimpossible to wholly eliminate the torsional deflection of the pinionsand relatively long gear carrying members and to maintain the weight andthe f size of the gearing within reasonable limits. The torsionaldeflection of a pinion results in an unequal distribution of toothpressure throughout the length of the intermeshing teeth because thelarger gears are in- I Specification of Letters Patent.

. mounted that its The dis- Patented Nov. 2, 1920;

Serial No. 103,93. Divided and this application filed February 4, 1919.Serial No. 274,974.

herently more rigid than the pinions and OR TO THE WESTING- aretherefore incapable of yielding in such a way as to compensate or evenpensate for the deflection of the pinion.

In United States Patent No. 946,455, issued to G. W. ,Melville and J. H.Maca-lpine, a reduction. gearing is shown in which one gear of theintermeshing pair is so partially comthe deflection or distortion isoccasioned by cross-bending or torsional deflection of the gear.

A specific object of my invention is to produce a double reductiongearmg in which the speed transformation is accomplished in two stepsand in which the large gear of one pair. of intermeshing gears is formedintegrally with, or otherwise operatively axis is, capable ofoccupyconnected to the small gear of the other in termeshing pair and.is capable of occu pying- I different angular positions with relatlonto the axis of the menu driven gear for the purpose of compensating fordistortion of the gears or for slight inaccuracies in workmanship. 1

' This, together with the previously enumerated objects, and otherobjects, to be made more apparent throughout the further description ofthe invention, are accomplished by means of apparatus embodying thefeatures herein described and illustrated.

In the drawings: Figure 1 is a plan view ofv areduction gearingembodying my invention.

Fig.2 is a fragmental vertical transverse sectional'view along the line2-2 of Fig. 1.

Fig. 3 is a transverse vertical sectional view along the linev 3-3 ofFig. 1.

In the illustrated embodiment of my invention, I have disclosed a maingear which is adapted to be operatively connected to the driven agent.Meshing with this main gear is a pinion which may be termed theintermediate pinion and is shown integrally intermediate pinion and theintermediate formed with a larger gear which may .be-

formed in two sets which are .gear wheel comprise an intermediate gearmember which is so mounted thatit 18 capable of occupying different anular positions with relation to the axis 0 the main gear for the purposeof compensating for the distortions of the gear or the gear memher andfor slight inaccuracies in worlnnanship. The driving pinion is also somounted that it is capable of angular motion with resion gearing inwhich the driven agent rotates at a speed greater than thatfof thedriving agent. It will be equally apparent to those skilled in the artthat the illustrated embodiment of my invention may be employed inaccomplishing such a speed transformation.

In the drawings I have illustrated a reduction gearing of the type inwhich power from more than one driving agent is transmitted to thedriven gear. It will, however, be understood that certain. and possiblythe principal features of the invention are applicable to and may beembodied in double reduction gearing receiving power from a singledriving agent. As shown, the'reduction gearing includes a main drivengear 5 which is journaled in av substantially rigid frame 6 and whichmay be operatively coupled to a driven agent such as a propeller shaft.The gear teeth of the gear 5 may be spiral or herringbone teeth and asshown are spaced apart.

Twointermediate pinions 7 and 7' mesh with the gear 5. The teeth ofthese pinions are formed in two sets which are spaced longitudinally ofthe intermediate member to correspond to the spacing ofthe sets of teethof the gear 5. Each inter'mediatepinion forms a partof an intermediategear member and is journaled in a floating frame 8. For convenience ofdescription I have applied the reference character 8' to the floatingframein which the pinion 7' is mounted. Each intermediate gear memberincludes an intermediate gear wheel which maybe formed integrally withthe pinionor which may be otherwise operatively connected to it. Asshown, the pinion 7 is integrally formed with a gear wheel 9, and thepinion 7 is integrally formed with a gear Wheel 9'.

rate pinion. The driving pinion 10 of the Each intermediate gear wheelmeshes with and is driven by a sepagear Wheel Sh wn journaled in afloating frame ,11 and is operatively connected to a driving agent 12 bymeans of a connection such as a 'flexible shaft 13. The-intermediategear wheel 9 meshes with and is driven by a driving pinion 10, which isoperatively coupled to the driving agent 12' by means of a flexibleshaft 13, and is journaled in a floating frame 11. p

For the purpose of equally distributing the stresses and strains betweenthe-different sets of teeth of each gear and also for the purpose ofminimizing the extent of the angular motion of the driving pinions andthe intermediate gear members, I have so formed and so arranged eachgear that the gearing is bilaterally symmetrical with relation to itstransverse axis which extends at right angles to the axis of the maingear 5, midway between the sets of teeth of that gear. With thisarrangement the stresses are not only equally distributed between thetwo sets of teeth of each gear but provision is also made for minimizingthe cross bending deflection of the pinions and gear members, since thespacing of the sets of gear teeth makes it possil le to employintermediate bearings for the pinions and the intermediate gear members.

As shown, the pinion 10 is provided with three bearings 14, 15 and 16.all of which are mounted on the floating frame 11. The

bearing 15 is located between the two sets of gear teeth a and b sothatthe pinion is supported by a bearing at a point intermediate itsends aswell as at points adjacent to its ends. The intermediate gearmember I is also provided with three bearings 17, 18

and 19, all of which are mountedJ-on the floating frame 8. The bearing18 islocatedmidway between the ends of the gear member, whereas theother two bearings are located at or near the ends of the member.

To accommodate this arrangement of bearings both the intermediate pinionand the intermediate gear wheel are in effect formed 111 two parts. Asshown, one set of gear teeth 0 of the gear wheel 9 is located on I,

one side of the bearing 18 and the other set d is located on theotherside of the bearing.

on the other side of the gear wheel, both being located between the endbearings. With this arrangement the two sets 0 and d of teethof thewheel 9 extend into the space between the two sets 9 and h of gear teethof the main gear 5. The arrangement of the 1 sets. of gear teeth andbearings of the intermediate pinion 7', gear wheel 9- and driving pinion11' correspond to the arrangement above described.

The illustrated mounting means of each of the frames 11, 11' consists ofoppositely i 'and berlpw the pinionand formed inte' rally disposedcylinders 21 gnd 22 located above with 0 secured to the floating frame.hese cylinders receive fluid or liquid under pressure from any suitablesource and each is shown provided with an operating plunger or piston 24which engages the main or stationary frame 6 of the gearing in such away as to permit the floating frame to assume different angularpositions with relation to the normal position of the axis of thepinion. The supply *of fluid under pressure delivered to the cylinders21 and 22 may be controlled as illustrated in Patent No. 1,136,189 toGeorge Westinghouse, and the c linder construction illustrated may berep aced by the arrangement of cylinders and pistons illustrated inWestinghouse Patent No. 1,088,387. With the arrangement of cylinders andpistdns illustrated or above described, each driving pinion will becapable of tilting about a pivotal point substantially midway betweenits ends, since the supporting p1stons are located symmetrically withrelation Y mediate gear member or of its mountingv to the sets of gearteeth of the pinion.

The floating frames in which the intermediate gear carrying members areour-- naled are illustrated as being mounted on the frame 6 by means ofan I-beam construction, the flexible web 25 of the I-beam being solocated that the pivot point of each interframe is located midwaybetween the ends of the gear member so that boththe gear.

member and the driving pinion, with which it cooperates, turn about thesame'axis in moving to different angular positions in planesperpendicular to the plane defined by the normal positions of theiraxes.

It will, of course, be understood that the floating frame 8 or 8' ofeach intermeshing gear member may be mounted on the main or stationaryframe 6'by means of a cylinder and piston construction similar to thatdescribed in connection with the driving pinionlO, or it may be mountedon the frame 6 in a manner substantially as illustrated in connect-ionwith the mounting of the pinion in Westinghouse Patent No. 1,088,387. It

will be apparent that the angular motion of each gear carrying member 19maybe 11mited to motion in one plane by the struts 26 shown in Fig. 4 orby struts similar to the struts l6 of Melville at al. Patent N 0.946,455. The main shaft of the gearing, that is the shaft 27, on whichthe main gear wheel 5 is mounted may be provided with a thrust bearing28 for the purpose of taking up longitudinal thrusts transmitted to theshaft 2 F Distortion of an intermediate gear member will cause the gearmember to move to an angular position such that the tooth pressurebetween the intermeshing geanteeth will be automatically distributed soas to equalize the tooth pressure throughout the length of each of theintermeshing teeth.

This angular movement of the intermediate 7 member, or a distortion ofthe intermediate member will distort the teeth-of the intermediate gearwheels, or will change the relative'positions of the two sets'of teethand will cause the cooperating driving pinion to move to anangularposition and to thereby compensate for the change in position of thentermediate gear carrying member or for the distortion of that member.The same action will result from a distortion of either omissions may bemade in the apparatus illustrated wlthout departing fromthe spirit'andscope of the invention asset forth by the appended claims.

What, I claim is:

1. In a transmission gearing, a driving gear having two sets of teethspaced apart axially of the gear, a driven gear having two sets of teethspaced apart axially of the gear, an intermediate gear member comprisingan intermediate gear wheel, having two sets of teeth spaced to conformto the spacing of the sets. of said driving gear and meshing with theteeth of said driving gear, and an intermediate pinion having two setsof teeth located on opposite sides of said gear wheel and meshing withthe teethof said-driven gear, means for mounting said intermediate gearmember so that it is capable of moving to different angular positionswith relation to the axis, of the" driven gear.

' 2. In a transmission gearing, a driving gear having two sets of teeth,a driven gear having two sets of teeth, an intermediategear membercomprising an intermediate gear wheel having two sets of teeth andmeshing with theteeth of said driving gear and an intermediate inionhaving two sets of teeth meshing with the teeth of said driven gear, theteeth of said intermediate pinion and gear wheel being symmetricallyarranged with relation to the transverse axis of said gearing, andvtiltable supporting means for the driving pinion and the intermediategear meniber whereby the axes of the driving pinion and the intermediategear member may move angularly.

3. In a transmission gearing, a driving gear, a driven gear, anintermediate gear membercomprlslng an intermediate pinion meshingwith-sald driven gear and an intermediate gear wheel meshing with saiddriying gear, a fioatingframe in which said intermediate gear member isjournaled, and means for mounting said frame Such that the axis of thegear member is capable of moving to different angular positions about apivot point located midway between its ends.

In a transmission gearing, a driving pinion. a driven gear, anintermediate gear member comprising a two part intermediate pinionmeshing with the driven gear and a two part intermediate gear wheelmeshing with the driving pinion, and mounting means for saidintermediate member such that said member is capable of moving todifferent angular positions about a pivot point located substantiallymidway between its ends, said two part gear wheel and pinion beingarranged symmetrically with relation to said pivot point.

In a transmission gearing, a driving pinion, a driven gear, anintermediate gear member, for transmitting power from the pinion to thegear, and mounting means for said member and said pinion whereby bothare capable of tilting to accomplish a uniform distribution of toothpressure, the pivot point about which said pinion tilts and the pivotpoint about which said intermediate gear member tilts defining a linewhich is substantially at right angles to the axis of the driven gear.

6. In a double reduction gearing, a two part driving gear, a two partdriven gear, resilient supporting means for the driving gear, anintermediate gear member including a two part intermediate gear meshingwith the driving gear and a gear on each side thereof meshing with thedriven gear,

- a resiliently supported frame in which the gear member is mounted, andsupporting means for said frame located at a pointintermediate the twoparts of the two part intermediate gear.

7. In a double reduction gearing, a driven gear, a driving gear and anintermediate gear member meshing with both said gears, said member andsaid driving gear both movable to angular positions in planesperpendicular to the plane defined by the normal positions of theiraxes, the pivot points about which said member and said driving gearmove defining a line substantially perpendicular to the normal positionof the axes of the gears.

8. In a double reduction gearing, a driven gear, two driving gears, aseparate intermediate gear member for transmitting power from eachdriving gear to said driven gear, a separate floating frame in whicheach gear member is journaled, and resilient support for each framelocated midway between the ends of the member journaled therein.

9. In a double reduction gearing, a two part driven gear, two two partdriving her for transmitting power from each driving gear to the drivengear, a separate floating frame in which each member is located, andsupporting means for each frame so arranged that each frame is capableof tilting about a point intermediate its ends for the purpose ofobtaining a uniform distribution of pressure along theintermeshingteeth, each intermediate gear member com prising a two part gear wheelmeshing with the driving gear and a; two part pinion meshing with thedriven gear, bearings for each gear member located at the ends thereofand at a point intermediate the ends, one of the parts of the pinion andof the gear wheel being located on each side of said intermediatebearing.

10. In a double reduction gearing, a pinion, a gear, an intermediategear member transmitting power from said pinion to said gear, a floatingframe in which said member is j ournaled and a fluid supported frame inwhich-said pinion is journaled.

11. In a reduction gear, the combination of a driving pinion memberhaving pinion portions, bearings for the pinion member, means forsupporting the bearings whereby the pinion member is capable of tiltingmotion about a point intermediate the pinion portions thereof, a drivenmember having gear portions, an intermediate member having pinionportions meshing with the gear portions of the driven member and gearportions meshing with the pinion portions of the pinion member, a framehaving bearings for the intermediate member, and flexible means forsupporting the frame at an intermediate point whereby the intermediatemember may tilt about a transverse axis.

12. In a reduction gear, the combination of a driven pinion memberhaving pinion portions, bearings for the pinion .member, means forsupporting the bearings whereby the pinion member is capable of tiltingmotion about a point intermediate the pinion ary, 1919.

FRANCIS HODGKINSON.

gears, a separate intermediate gear'mem-

